virius removal on a storage drive

I recently got a virius on my storage drive(E:\).I did run a few AV’s before I actully caught it.I did quarrentined it but havent removed it as of yet.
I have 2 problems one is..I dont want to format the drive and wipe out 200gb of stuff.The second is my PC is running very slow now almost 3 full mins to boot up.
I have done 2 new installs of windows on the 80gb and its still very slow.
My main concern is…has the virius spread and my AV is not picking it up?Or is it that becasue it quarrentied and not acctuly gone.
I tryed to use highjackthis but it only shows the c:\ drive.
My specs are
amd 64 x2 4600
7900gt ko
2gb pc3200 kingston ram
80gb maxtor
250gb seagate
win xp pro sp2